Voltage divider calculator

It is used to calculate the voltage drops on the individual resistor load when it is connected in a sequence. It has four text fields which require you to enter the total voltage, the resistance of the first, second and third load. The first and second charge are necessary, and the third load resistance is usually optional. Once all these values have been filled in their respective fields, you can press the ‘Calculate' button to give you the voltage drops of the loads in the sequence.

There are two types of voltage divider rule which involve the Direct Current (DC) circuit and the Alternating Current (AC) circuit

DC Circuit Voltage Divider Rule

Vi = VT Ri________
R1 + R2 + R3 + …

Where;
• Vi is the voltage drop in volts and VT is the voltage drop or voltage source equivalent in volts
• Ri is the resistance of resistor in ohms (Ω)
• R1 is the resistance of resistor R1 in ohms (Ω)
• R2 is the resistance of resistor R2 in ohms (Ω)
• R3 is the resistance of resistor R3 in ohms (Ω)

For example;

The voltage source of VT is 20 V. It is connected to R1 and R2 resistors in the series with 40 (Ω) and 50 (Ω) respectively. What is the voltage drop on Resistor R2?

Solutions;

V2 = VT x R2 / (R1 + R2)

= 20 V x 50Ω / (40Ω + 50Ω) = 11.11 Volts (V)

AC circuit Voltage Divider Rule

An Alternating Current Circuit having loads in series and voltage source, the formula of the load and voltage drop will be given by;

Vi = VT Zi____
Z1 + Z2 + Z3 …

Where;
• Vi is the voltage drop in volts (V) and load Zi
• VT is the voltage drop in volts or the equivalent voltage source
• Zi is the impedance of load Zi in ohms (Ω)
• Z1 is the impedance of load Z1 in ohms (Ω)
• Z2 is the impedance of load Z2 in ohms (Ω)
• Z3 is the impedance of load Z3 in ohms (Ω)